If water freeze at 0, why doesnt it freeze under 0?

Question

Its like -5 now.

Why isnt the water outside in the air, frreze into ice?

Answer 1

He's right, you would need high humidty and eventually saturation before water in the air is plentiful enough to condense. There's not enough moisture in the air for the water vapor to condense so if it can't become a liquid how could it become ice?

Answer 2

Because it's already frozen

Answer 3

It can, if the humidity is high and the water vapor in the air becomes droplets of liquid water.  It's called an "ice fog".

As the temperature drops, the air can hold less water.  That's why you see fogs and frosts early in the day when it is coolest.

DK

Answer 4

Answers are right... with this extra info.

I assume you mean the water "outside in the air" not only to mean the water vapor in the atmosphere, but puddles of water on the ground, or lakes.

There are a number of reasons that a puddle of water may not be frozen even though the ambient air temperature is below freezing.

The first is that to actually freeze, water needs to absorb additional energy, sometimes called the "heat of fusion."  So beyond just the air temperature, there must be this additional loss of energy for the water to change forms.  Because water doesn't absorb or give off energy particularly well (compared to, say, metal), it takes time for water to absorb this energy and change states.  That's enhanced if the water is particularly thick.  That's why lakes take months to freeze, and most lakes don't freeze all the way through.  

In addition, the ground near the water may not be at the freezing point (because ground takes even more time to rid itself of heat). So the air temperature may be -5, but the ground temperature may be 5 or 10, keeping the water in its liquid state.